1868868691 has 2 divisors, whose sum is σ = 1868868692. Its totient is φ = 1868868690.

The previous prime is 1868868689. The next prime is 1868868737. The reversal of 1868868691 is 1968688681.

It is a weak prime.

It is an emirp because it is prime and its reverse (1968688681) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1698988981 and 1898898961.

It is a cyclic number.

It is not a de Polignac number, because 1868868691 - 2¹ = 1868868689 is a prime.

Together with 1868868689, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1868868641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 934434345 + 934434346.

It is an arithmetic number, because the mean of its divisors is an integer number (934434346).

Almost surely, 2^1868868691 is an apocalyptic number.

1868868691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1868868691 is an equidigital number, since it uses as much as digits as its factorization.

1868868691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7962624, while the sum is 61.

The square root of 1868868691 is about 43230.4139582308. The cubic root of 1868868691 is about 1231.7604709019.

The spelling of 1868868691 in words is "one billion, eight hundred sixty-eight million, eight hundred sixty-eight thousand, six hundred ninety-one".